Valken RDA20 Mini Red Dot SightDescription : The Valken RDA20 Mini Red Dot Sight is a low profile airsoft optic with a 20mm tube diameter. The RDA20 has a strong and lightweight nylon fiber reinforced housing, and mounts to most 20mm picatinny and weaver rails. This airsoft red dot includes a CR1620 battery to illuminate the bright single red dot reticle with 5 brightness settings. The red dot offers a phase coated lens for a clear image with true color, and the turret click value